How To Watch The Solar Eclipse Without Going Blind

Monday, Aug. 21, 2017. It’s an important date for astronomy nerds and casual space enthusiasts alike because on that day, a total solar eclipse will dramatically alter the American sky. While the Earth experiences a total solar eclipse about once every 18 months, Americans won’t see another one for seven years. This year, for a lucky strip of the U.S., the moon will look identical to the sun in size, blocking all the sun’s light for a few unnerving minutes. An optical illusion of cosmic proportions, it’s an event you don’t want to miss.

But how can you safely watch the eclipse without scalding your retinas, you ask? Most days, it’s simple: Don’t look at the sun. On Aug. 21, that precaution gets a little tricky since you’ll want to soak up the full impact of our solar system’s rare instance of solar-lunar alignment. Unless you plan on looking straight up from within the “totality” – the slim band across the U.S. that’ll be in total darkness – the moon won’t block the sun all the way, acting like more of a dimmer switch than blackout shades. Even if you’re in the totality’s path, the moon will block the sun for less than two minutes, so you’ll want to have backup protection regardless.

According to NASA, there are “eclipse glasses” you can use to protect your eyes from the sun’s damaging rays — though they must meet international standards, be less than three years old, and “have the manufacturer’s name and address printed somewhere on the product.” They look like the 3D glasses you grab at the movie theater and are the only NASA-approved devices for looking at the sun, next to handheld viewers. The space agency warns users to check their eclipse glasses for scratches or any signs of damage before use. If they appear damaged at all, toss them and get new ones. Better safe than needlessly blind, right?